Closure cap and package formed therewith

ABSTRACT

A closure cap of the press-on turn-off type having a gasket retaining channel formed with a frusto-conical inner wall which cooperates with the relatively abrupt inside top radius or corner of the relatively wide flat top seal finish of a container. The inside top radius or corner acts as a circumferential ridge that deeply indents the gasket material so as to pinch the opposing gasket material between the frusto-conical channel sidewall and the abrupt radius into a thin annular section which acts to minimize oxygen permeation and also to prevent cap settling with resultant increase of removal torques.

[ 51 Sept. 12, 1972 United States Patent Lecinski, Jr.

3,371,813 3/1968 Owen et ....2l5/40 FORMED THEREWITH Primary Examiner-George T. Hall Attorney-Creist, Lockwood, Greenawalt & Dewey [54] CLOSURE CAP AND PACKAGE ABSTRACT A closure cap of the press-on tum-off type having a gasket retaining channel formed with a frusto-conical inner wall which cooperates with the relatively abrupt inside top radius or comer of the relatively wide flat top seal finish of a container. The inside top radius or mm O89 mYhM mwmn

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R f cud sidewall and the abrupt radius into a thin annular sece erences tion which acts to minimize oxygen permeation and UNITED STATES PATENTS also to prevent cap settling with resultant increase of removal torques.

Hart et al.....................215/40 Zipper et a1. ................2l5/40 10 Claims, 4 Drawing Figures PATENTEDsEP 12 m2 l'll llll

Hilli- INVENTOR FRANK H. LEC/NSKLJR.

- ATT 'Ys CLOSURE CAP AND PACKAGE FORMED THEREWlTI-I This invention relates generally to innovations and improvements in closure caps of the press-on tum-off type having a cap body provided with a ring gasket, in part retained in a channel at the margin of the top panel of the cap and, in part extending down the depending skirt thereof.

More particularly, the invention relates to innovations and improvements in such closure caps wherein the gasket retaining channel has a frusto-conical inner sidewall for use on a container having a closure engaging finish which has a flat top seal portion with a relatively abrupt inside top radius or comer which deeply indents the gasket material opposite an intennediate portion of the frusto-conical channel wall so as to pinch off the gasket material therebetween into a relatively thin cross-section which serves to minimize oxygen permeation into the head space of the container and at the same time serves to prevent settling of the cap with resultant undesirable increase in removal torque.

Closure caps of the present invention presently will be primarily used on glass containers for the packaging of various food products. The caps are applied at high speeds (e.g. up to 1,000 per minute) onto containers by a straight down pressing action using capping machines of known type. For example, large quantities of these caps will be used in the packaging of baby foods in glass ars.

The gasket materials used in the closure caps of the present invention are preferably formed of plastisol type gasket compounds of known type (e.g. as described in US. Pat. No. 2,841,304) which are moulded or flowed into the cap shells in known manner using commercially available equipment and techniques. The closure caps of the present invention are intended for use on containers formed of glass or other materials wherein the gasket engaging surfaces include a flat top seal finish and a side seal finish having thread formations thereon or therein. On standing after cap application the plastisol gasket material within the skirt portions of the closure cap shells conforms to the thread formations and takes a set so that complementary thread formations are efi'ectively formed in the plastisol gasket material. The resulting complementary thread formations in the gasket material serve to earn up the closure caps when the same are rotated so that the caps may be readily removed (i.e. unscrewed) from the containers.

Closure caps of the general type to which the present invention relates are disclosed in the following US. Pat. Nos.: 3,270,904; 3,285,452; 3,344,943; 3,360,148; 3,371,813; 3,374,601; 3,448,881; and, 3,473,683.

The object of the invention generally stated is the provision of a press-on tum-ofi closure cap of the type or class described, together with a package formed or completed by such a cap when applied to a container having a gasket engaging sealing finish of the type described with (1) the inner sidewall of the channel retaining the top seal portion of the gasket in the form of a relatively wide frusto-conical section of the cap top panel and (2) the narrow ridge-like inside top radius or corner of the flat to seal finish of the capped container deeply indenting the gasket material opposite the mid portion of the frusto-conical section thereby pinching off the gasket material caught therebetween into an annular thin cross sectional area which serves to minimize oxygen permeation into the cap head space from the outside and prevent cap settling thereby preventing removal torques from increasing on standing.

A further and important object of the invention is the provision of closure caps of the type described, and packages of the type formed therewith, wherein the relatively wide inclined section of, the cap top panel that forms the frusto-conical inner wall of the gasket channel, in combination with the container sealing finish having a relatively abrupt ridge-like inside top radius, minimizes the effects of variation in the cap panel depth and in glass diameters so that tolerances in respect to these dimensions are less critical.

A further object of the invention is the provision of closure caps of the press-on turn-off type having the above-mentioned innovations and improvements wherein the depending skirt portions of the caps are essentially straight sided for cooperation with thread formations in the side finish of the container wherein the crests of the threads lie in essentially a vertical cylinder thereby eliminating the tightening effect and increase in removal torque due to any closure settling that may occur.

Certain other objects of the invention will be obvious and others appear hereinafter.

For a more complete understanding of the nature and scope of the invention, reference may now be had to the following detailed description thereof taken in connection with the accompanying drawings as, wherein:

FIG. 1 is a top plan view of a closure cap forming one embodiment of the present invention;

FIG. 2 is a vertical sectional view taken on line 2-2 of FIG. 1 with the closure cap superposed over the neck or mouth of a container having the proper gasketengaging finish;

FIG. 3 is a fragmentary sectional view on an enlarged scale of the right hand portion of the closure cap as shown in FIG. 2; and,

FIG. 4 is a fragmentary sectional view on an enlarged scale corresponding to FIG. 3 showing the relationship between the closure cap and the gasket-engaging finish of the container neck or mouth.

In the drawings, a closure cap is indicated generally at 5 comprising a cap shell or body which has a top panel portion 6 and a depending skirt or sidewall portion 7. The cap 5 is lined with an integral ring gasket having a top seal portion 8 that lies within the gasket channel of the cap indicated at 10 and a side seal portion 1 l lining the inner surface of the cap skirt 7.

The central portion of the top panel 6 of the cap body is preferably raised with a particular formation that forms a tamper-tell button 12. This button 12 may be made in accordance with the disclosure of Foster US. Pat. No. 3,160,302. When the cap 5 is used on a package in which a vacuum is formed in the head space the button 12 will be held inwardly or downwardly depressed under the influence of the vacuum. However, if the cap 5 is rotated or tampered with so as to break the vacuum then the depressed button portion 12 snaps outwardly with an audible click.

The cap bodies or shells may be stamped or otherwise formed from tin plate, aluminum sheet, or other suitable material on a mass production basis in a well known manner using known equipment. The shells or bodies may be suitably enameled, lacquered or otherwise coated or surface-treated on the interiors and exteriors with protective and decorative enamels or coatings which are well known in the closure cap art.

The ring gasket 8, 11 within the cap body is preferably formed of a plastisol'of known composition and may be of the so-called puffed variety if desired. The gasket may be deposited or molded into the cap shell in known manner such as in accordance with the teachings of US. Pat. Nos. 3,360,148 or 3,473,683. After the plastisol gasket material has been deposited or molded, the lined or gasketed caps are submitted to a fluxing operation of known type wherein the plastisols are fluxed into their final resilient rubber-like condition.

The details of the construction and configuration of the gasket retaining channel and of the cooperating gasket-engaging finish of the container 19 are highly important in certain respects and will be described in connection with FIGS. 3 and 4. In these figures it will be noted that the gasket retaining channel 10 of the cap body which serves to retain the top fmish-engaging portion 8 of the gasket is formed by a frusto-conical or straight inclined annular inner wall portion 15 and an arcuate or curved outer wall portion 16. In production the top seal gasket portion 8 of the ring gasket which is retained in the gasket channel 10 fills this channel substantially flush and when produced in accordance with the teachings of Owen US. Pat. No. 3,360,148, the then inner margin of the gasket section 8 terminates in a cut ofi' rib or ridge 17 It will be seen from FIG. 3 that the radial width or dimension of the frusto-conical inner sidewall 15 of the top seal gasket channel 10 is approximately twice the radial width of the arcuate outer sidewall 16. While this particular relationship is not critical, the frusto-conical inner wall 15 should be substantially wider than the outer arcuate portion. It will be seen that the depending skirt 7 of the cap 5 has a cylindrical upper section 18 which merges into a frusto-conical section 20 which merges into a relatively wide or deep cylindrical section 21. The bottom end of the skirt is in the form of an outwardly flared inwardly curled bead 22 formed in the usual manner.

The vertical or side seal portion 11 of the gasket is relatively thick until it thins out into a feather edge at the bottom where the cap shell flares outwardly into the head or curl 22.

In FIG. 4 the mouth 25 of the glass container 19 has both a top seal finish and a side seal finish, referring to the surfaces of the top or rim and the outer side wall of the container mouth 25. These are the surfaces of the container 19 which engage the gaket material in the cap 5 and are made to specific dimensions with closely controlled tolerances.

The top seal finish of the container mouth includes a relatively wide flat annular surface 26 which at the inner edge merges with the vertical inside surface at a circumferential comer 27 which is referred to in the art as the inside top radius. This inside top radius 27 provides a smooth but relatively abrupt inner edge or comer which has the specific and important function of deeply indenting the top seal gasket portion 8 at an intermediate part of the frusto-conical channel wall 15.

The side seal finish of the container 5 has a slightly tapered upper portion 30 and a cylindrical lower portion 31. Intermediate these portions the side finish is provided with protruding thread formations 32 the crests of which lie in a generally vertical cylinder surface. It will be understood that while the thread formations 32 constitute portions of one continuous thread they may take the form of a plurality of partial threads as shown in FIG. 4 of US. Pat. No. 3,270,904.

The caps 5 are applied to containers 19 with a generally straight-down motion which the side seal portion 11 of the gasket deforms sufficiently so as to pass over the thread formations. In many instances, the head space within the filled containers will be filled with steam when the closure caps are applied. When the steam condenses the resulting vacuum serves to tightly retain the closure caps on the container mouth or neck. It will be seen that the inside top radius 27 of the container finish deeply indents the top seal portion 8 of the ring gasket opposite, to close proximity to a narrow intermediate band portion of the frusto-conical section 15 of the gasket channel. The gasket material 8 is pinched or squeezedin both directions with respect to the relatively narrow inner comer 27 so that only a relatively thin section 35 of gasket material remains to separate the glass at the comer 27 from the opposing frusto-conical wall 15. This section 35, however, has appreciable radial width. Because of the thinness of the section 35 and its appreciable radial width it constitutes a barrier path which offers a high degree of resistance to oxygen permeation inwardly into the container or package contacts. In other words, permeation of the gasket is confined to travelling through this very thin section which constitutes a relatively long (i.e. radially wide) and narrow path for the gas travel.

This relationship or co-action between the top inside corner or inside top radius 27 of the glass finish and the opposing frusto-conical section 15 of the gasket retaining channel 10 also serves a further function. That is, this relationship prevents and limits downward settling of the cap 5 on the container finish 25. This in turn prevents tightening of the compressive embracing aca cylindrical surface) any slight settling of the cap 5 that does occur will not produce a tightening effect with respect to the threads.

It will be seen from the relationship shown in FIG. 4 between the frusto-conical section 15 of the gasket channel 10 and the inside top corner or radius 27 that slight variations in the formation and dimensions of these cooperating parts do not appreciably change or alter the essential relationship. Accordingly, small variations in these dimensions or parts are not objectionable thereby facilitating the mass production of the closure caps and the containers.

It is understood that on standing the gasket material takes a permanent set where it is deformed to receive the thread formations 32 and in efl'ect female threads are thus molded or formed in the side seal gasket portion 11 of the gasket. According y, when the cap is rotated it will be cammed off from the container finish 25 in known manner.

I claim:

1. In combination with a container having a closureengaging finish which includes a flat top seal portion with a relatively abrupt inside top radius and an exterior side seal portion, a closure cap comprising a cap body and a fluxed plastisol integral ring gasket therein having top seal and side seal portions, said cap body having a top panel and a depending skirt, the annular margin of said top panel being in the form of a gasketretaining channel and having a relatively wide frustoconical inner portion which extends from the center portion of said top panel upwardly and outwardly to a relatively narrow outer arcuate portion, said integral ring gasket lining said channel and said depending skirt, said top and side seal portions of said container closure-engaging finish and said cap body skirt and gasket material-retaining channel being so relatively proportioned that when said closure cap is in full sealing engagement on said closure-engaging finish said relatively abrupt inside top radius deeply indents said gasket material to close proximity to a narrow intermediate band of said frusto-conical portion of said gasket retaining channel.

2. In combination with a container having a closureengaging finish which includes a flat top seal portion with relatively abrupt inside top radius and an exterior side seal portion having thread-like camming formations thereon, a press-on, turn-off closure cap comprising a cap body and a fluxed plastisol integral ring gasket therein having top seal and side seal portions, said cap body having a top panel and a depending skirt, the annular margin of said top panel being in the form of a gasket-retaining channel and having a relatively wide frusto-conical inner portion which extends from the center portion of said top panel upwardly and outwardly to a relatively narrow outer arcuate portion, said integral ring gasket lining said channel and said depending skirt, said top and side seal portions of said container closure-engaging finish and said cap body skirt and gasket material-retaining channel being so relatively proportioned that when said closure cap is in full sealing engagement on said closure-engaging finish said relatively abrupt inside top radius deeply indents said gasket material to close proximity to a narrow intermediate band of said frusto-conical portion of said gasket-retaining channel and the portion of said ring gasket lining said skirt extending down at least far enough to compressingly embrace said thread-like camming formations.

3. In the combination called for in claim 1 said frusto-conical inner portion of said gasket-retaining channel having a radial width appreciably greater than the radial width of said flat top seal portion of said closure-engaging finish.

4. In the combination called for in claim 1 said frusto-conical inner portion of said gasket material channel having a radial width at least about 1.5 times the radial width of said relatively narrow outer arcuate portion thereof.

5. In the combination called for in claim 1 said frusto-conical inner portion of said gasket retaining channel having an angle of inclination not exceeding about 30.

6. In the combination called for in claim 1 said gasket retaining channel having a radial width at least about 1.5 times the radial width of said flat top seal portion of said closure-eng ng finish.

7. In the com ination called for in claim 2 said thread-like camming formations being exterior thread formations with the crests lying in a vertical cylinder.

8. A closure cap for a container having a closure-engaging finish which includes a flat top seal portion with a relatively abrupt inside top radius and an exterior side seal portion having exterior thread-like camming formations thereon, said closure cap comprising a cap body and a fluxed plastisol integral ring gasket therein having top seal and side seal portions, said cap body having a top panel and a depending skirt, the annular margin of said top panel being in the form of a gasketretaining channel and having a relatively wide frustoconical inner portion which extends from the center portion of said top panel upwardly and outwardly to a relatively narrow arcuate portion, said integral ring gasket substantially filling said channel and lining said depending skirt.

9. The closure cap of claim 8 wherein said frustoconical inner portion of said gasket-retaining channel has a radial width at least about 1.5 times that of said relatively narrow outer arcuate portion thereof.

10. The closure cap of claim 8 wherein said frustoconical inner portion of said gasket-retaining channel has an angle of inclination not exceeding about 30. 

1. In combination with a container having a closure-engaging finish which includes a flat top seal portion with a relatively abrupt inside top radius and an exterior side seal portion, a closure cap comprising a cap body and a fluxed plastisol integral ring gasket therein having top seal and side seal portions, said cap body having a top panel and a depending skirt, the annular margin of said top panel being in the form of a gasket-retaining channel and having a relatively wide frusto-conical inner portion which extends from the center portion of said top panel upwardly and outwardly to a relatively narrow outer arcuate portion, said integral ring gasket lining said channel and said depending skirt, said top and side seal portions of said container closureengaging finish and said cap body skirt and gasket materialretaining channel being so relatively proportioned that when said closure cap is in full sealing engagement on said closureengaging finish said relatively abrupt inside top radius deeply indents said gasket material to close proximity to a narrow intermediate band of said frusto-conical portion of said gasket retaining channel.
 2. In combination with a container having a closure-engaging finish which includes a flat top seal portion with relatively abrupt inside top radius and an exterior side seal portion having thread-like camming formations thereon, a press-on, turn-off closure cap comprising a cap body and a fluxed plastisol integral ring gasket therein having top seal and side seal portions, said cap body having a top panel and a depending skirt, the annular margin of said top panel being in the form of a gasket-retaining channel and having a relatively wide frusto-conical inner portion which extends from the center portion of said top panel upwardly and outwardly to a relatively narrow outer arcuate portion, said integral ring gasket lining said channel and said depending skirt, said top and side seal portions of said container closure-engaging finish and said cap body skirt and gasket material-retaining channel being so relatively proportioned that when said closure cap is in full sealing engagement on said closure-engaging finish said relatively abrupt inside top radius deeply indents said gasket material to close proximity to a narrow intermediate band of said frusto-conical portion of said gasket-retaining channel and the portion of said ring gasket lining said skirt extending down at least far enough to compressingly embrace said thread-like camming formations.
 3. In the combination called for in claim 1 said frusto-conical inner portion of said gasket-retaining channel having a radial width appreciably greater than the radial width of said flat top seal portion of said closure-engaging finish.
 4. In the combination called for in claim 1 said frusto-conical inner portion of said gasket material channel having a radial width at least about 1.5 times the radial width of said relatively narrow outer arcuate portion thereof.
 5. In the combination called for in claim 1 said frusto-conical inner portion of said gasket retaining channel having an angle of inclination not exceeding about 30*.
 6. In the combination called for in claim 1 said gasket retaining channel having a radial width at least about 1.5 times the radial width of said flat top seal portion of said closure-engaging finish.
 7. In the combination called for in claim 2 said thread-like camming formations being exterior thread formations with the crests lying in a vertical cylinder.
 8. A closure cap for a container having a closure-engaging finish which includes a flat top seal portion with a relatively abrupt inside top radius and an exterior side seal portion having exterior thread-like camming formations thereon, said closure cap comprising a cap body and a fluxed plastisol integral ring gasket therein having top seal and side seal portions, said cap body having a top panel and a depending skirt, the annular margin of said top panel being in the form of a gasket-retaining channel and having a relatively wide frusto-conical inner portion which extends from the center portion of said top panel upwardly and outwardly to a relatively narrow arcuate portion, said integral ring gasket substantially filling said channel and lining said depending skirt.
 9. The closure cap of claim 8 wherein said frusto-conical inner portion of said gasket-retaining channel has a radial width at least about 1.5 times that of said relatively narrow outer arcuate portion thereof.
 10. The closure cap of claim 8 wherein said frusto-conical inner portion of said gasket-retaining channel has an angle of inclination not exceeding about 30*. 